Crane with telescopic boom

ABSTRACT

A means and technique are disclosed for latching and unlatching the telescoping boom sections of a crane boom or other outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal. In the device, there are three elongated boom sections, the intermediate and the uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof. The intermediate and uppermost sections are latched against relative reciprocation when they are in the relatively extended condition thereof, by latch means which are operatively interposed therebetween. In addition, the intermediate and uppermost sections are maintained in relatively extended condition with respect to the lowermost section, and released for relative retraction, by means including a latch release member which is mounted on the lowermost section and operative to release the latch means between the intermediate and uppermost sections when the latter sections have travelled a predetermined distance in relation to the lowermost section.

United States Patent Fikse July 4, 1972 [54] CRANE WITH TELESCOPIC BOOM [72] Inventor:

[73] Assignee:

Tyman II. Fikse, Enumclaw, Wash.

Tyee Construction Company, Kirkland, Wash.

[22] Filed: March 25,1970

[2]] Appl.No.: 22,542

Primary ExaminerEvon C. Blunk Assistant ExaminerMerle F. Maffei Att0meyChristensen & Sanborn [57] ABSTRACT A means and technique are disclosed for latching and unlatching the telescoping boom sections of a crane boom or other outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal. In the device, there are three elongated boom sections, the intermediate and the uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof. The intermediate and uppermost sections are latched against relative reciprocation when they are in the relatively extended condition thereof, by latch means which are operatively interposed therebetween. In addition, the intermediate and uppermost sections are maintained in relatively extended condition with respect to the lowermost section, and released for relative retraction, by means including a latch release member which is mounted on the lowermost section and operative to release the latch means between the intermediate and uppermost sections when the latter sections have travelled a predetermined distance in relation to the lowermost section.

12 Claims, 1 1 Drawing Figures PATENTEnJuL 4 I972 SHEET Q [If 4 CRANE WITH TELESCOPIC BOOM FIELD OF THE INVENTION This invention relates to outrigger devices which are mounted on anchorages to be pivoted into operatively inclined positions relative to the horizontal, and which can be extended and retracted to various operative lengths. In particular, it relates to devices of this nature which comprise two or more elongated boom sections that are relatively reciprocably engaged to be extended and retracted in relation to one another along the length of the device while it is in the operatively inclined position thereof.

BACKGROUND OF THE INVENTION INCLUDING CERTAIN OBJECTS THEREOF The difficulty with land borne outrigger devices such as cranes, fire fighting towers and the like which are operated from anchorages on the ground is that they are difficult to transport from one point to another because of the cumbersome lengths thereof. For this reason, most such devices comprise a plurality of boom sections which can be dismantled and reassembled from one point to another, to assure that the collapsed length of the device is a more manageable dimension from the standpoint of traveling over roads and the like. However, the task of dismantling and assembling the sections is a laborious and time-consuming process, and is particularly annoying when the device is to be shifted simply from one location to another at a single building site, such as for purposes of making separate concrete pours at two or more locations around the site.

One object of the present invention, therefore, is to provide a sectionalized device of this nature which requires no such process, and in fact, can be extended and retracted along the length thereof, while the device is in its operative position on an incline to the horizontal. Another object is to provide a device of this nature which can be either raised or lowered to or from its fully extended operative position in as little as l5 or minutes. A further object is to provide a device of this nature which is raised and lowered by one pendant when fully collapsed, and then supported by a second and separate pendant when raised and in fully extended condition along its operative incline to the ground. Other objects include the provision of a device of this nature in which the boom sections are securely latched against relative reciprocation in the extended condition of the device, and yet are automatically unlatched from one another as the device is collapsed, once the next to lowermost section has been unlatched from the lowermost. Still further objects will become apparent from the description of the invention which follows hereafter.

SUMMARY OF THE INVENTION These objects and advantages are realized by a means and technique of my invention wherein the device is raised and lowered to and from the operatively inclined position thereof, and supported in said position by means which include a pair of pendants that are operatively interconnected between the anchorage and the aforesaid boom sections, and each individually operative to assume support of the device when in tension. in addition, there are control means connected to one of the pendants which are operative to shifi the support of the device from the one pendant to the other, and vice versa, by altering the tension in the aforesaid one pendant so as to pivot the device either toward or away from the horizontal when the other pendant is taut. Preferably, the control means are operable to alter the tension in the one pendant by adjusting the effective length of the same, relative to a straight line course between its connections with the anchorage and the device. For example, by forming a bend in the one pendant, transverse to the aforesaid course, the control means may operate to shorten its effective length and thus to pivot the device upwardly away from the horizontal. On the other hand, by collapsing such a bend, the control means operates to lengthen its effective length so as to lower the device relatively toward the horizontal. Therefore, in preferred embodiments of the invention, the control means include a reciprocable control member which is operable to form and collapse such a bend in its opposing directions of reciprocation.

In these embodiments, moreover, one of the aforesaid boom sections is pivotally connected to the anchorage, whereas the other is carried on the one section and telescopically engaged therewith to be extended and retracted in relation to it along the operative incline of the device. The reciprocable control member is interposed between the one section and the pendent which is connected therewith from the anchorage; and includes a hydraulic cylinder, the piston of which is operable to form the bend in one direction of its reciprocation, and to collapse the bend in the other direction.

The pendant connected with the other section is rigged in twoparts about a sheave thereon; and there are stops on the other section and the latter pendant which abut one another when the other section has assumed its extended position and the latter pendant is taut. I

Generally, there are means for extending and retracting the other section in relation to the aforesaid one section, which are separate from and independent of the means for raising, lowering and supporting the device. Also, the other section may include two or more subsections which are relatively reciprocably engaged with one another, for extension and retraction in relation to one another, as well as being conjointly relatively reciprocably engaged with the one section as described above.

Various means and techniques may be employed for latching the pair of boom sections to one another when they are in their relatively extended condition, and for releasing the latch means when the sections are relatively retracted or collapsed. However, the same is not true of any such means for maintaining the aforesaid two or more subsections in relatively extended condition, and collapsing the same, since in this instance the subsections are also conjointly reciprocable in relation to the one section, and this fact complicates the latching and unlatching procedure. Therefore, according to the invention, the device further comprises latch release means which are mounted on the one section, and movable in relation thereto, in response to release of the latch means between the one section and the other section, to release the latch means between the subsections when the other section has traveled a predetermined distance in relation to the one section, such as when the relatively lower subsection of each pair of subsections has retracted into the one section from the extended position thereof. In the preferred embodiments of the invention, there is a recess in the relatively upper subsection of each pair, and a pawl which is carried on the relatively lower subsection, and operatively interposed between the recess and the adjacent end portion of the lower subsection to latch the subsections against relative reciprocation in the ex tended condition thereof. The latch release means includes a displacement member for the pawl which is carried on the one section and engageable with the pawl at a point in the travel of the other section at which the subsections are caused to travel at a difierential rate of speed in relation to the one section, so that the pawl is displaceable from the recess when engaged by the displacement member. For example, for this purpose the means for extending and retracting the other section in relation to the one section, may include means for braking the relatively upper subsection in relation to the lower subsection, at the point where the pawl and the displacement member engage one another. Preferably, the pawl is mounted on the lower subsection at a relatively laterally outwardly spaced fulcrum point thereon, and the displacement member is operatively inserted in the space between the lower subsection and the aforesaid fulcrum point thereon, to release the pawl when the lower subsection is fully retracted in the one section. Also, the displacement member is constituted by another pawl which is operatively interposed between a recess in the lower subsection and the adjacent end portion of the one section to latch the sections against relative reciprocation, there being manually-operated means for releasing this latter pawl from the latch position thereof when the aforesaid other section is to be retracted in relation to the one section.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features of the invention will be better understood by reference to the accompanying drawings which illustrate the invention as it is applied to a mobile crane having a telescopic boom thereon.

In the drawings, FIG. 1 is a schematic side elevational view of the crane showing the boom in its collapsed or fully retracted condition, both as the boom is disposed in traveling position substantially horizontal to the ground, and as it is disposed in operative position relatively inclined to the ground;

FIG. 2 is a similar view showing the boom in its partly extended condition when operational;

FIG. 3 is another such view showing the boom in its fully extended condition when operational;

FIG. 4 is a greatly enlarged part side elevational view of the boom, when it is partially extended and supported by the shorter pair of four pendants connected therewith;

FIG. 5 is another greatly enlarged part side elevational view of the boom when it is fully extended and supported by the longer pair of the pendants;

FIG. 6 is a third such view showing the boom in its fully collapsed or retracted condition and again supported by the shorter pair of pendants;

FIG. 7 is a part cross-sectional view through the boom in the region of a hydraulic cylinder mechanism by which the support of the boom is shifted from one pair of pendants to the other;

FIG. 8 is a part cross-sectional view through the boom in the upper end region of the uppermost section, showing the blocks by which the longer pendants are attached thereto;

FIG. 9 is a greatly enlarged part cross-sectional view of the boom showing the manner in which the sections of the same are telescopically engaged with one another;

FIG. 10 is a part side elevational view of the boom showing the manner in which the sections are latched against reciprocation when extended; and

FIG. 11 is another such view showing the manner in which the sections are unlatched when the boom is collapsed from its extended condition.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, it will be seen that the boom 2 of the crane is pivotally mounted at the forward end of a supporting platform 4 that is rotatably supported in turn ona wheeled chassis 6 so that the boom can be swung to either side of the chassis during the operation of the crane at different sites on the ground 7. The platform 4 also carries a cab 8 for housing the operator and his controls, and in use the boom is raised, lowered and supported from the cab by a cable connected sheave and drum winding mechanism 10 which is rigged through a fair-leader 12 disposed upright on the top rear of the cab. The drums 14 in the mechanism are carried in the cab, while the sheaves 16 are carried in a bridle 17 which is connected to the boom in turn by a pair of pendants l8 and 20, each of which is duplicated in the system, for safety, although it is individually capable of supporting the boom when in tension, as shall be explained.

The boom 2 itself has three telescoping sections, the lowermost and telescopically outermost of which 2' is pivotally anchored to the platform to be swung between a lowered traveling position illustrated in dot-dash lines in FIG. 1, and one of several raised positions which are operatively inclined to the supporting ground 7 therebelow, as illustrated by the full-lined representations of FIGS. 1-3. The remaining two sections, or subsections 2" and 2", are normally retracted and nested within the lowermost section 2' while the latter is held in its traveling position, but they may be extended in relation to the lowermost section, as in FIGS. 2 and 3, when the crane is put to use. The extension process is double-staged in that the uppermost section 2" is-extended in relation to the intermediate section 2", as in FIG. 2, even before the latter section is extended from its nested condition within the lowermost section, as in FIG. 3. The means for carrying out the process include a further cable-connected sheave and drum winding mechanism 22 which is rigged up and back through the sections, after passing over a smaller-sized fairleader 24 at the base of the lowermost section. In this latter mechanism, certain of the sheaves are arranged as comer blocks 26 at the lower ends of the sections, while the remainder are arranged as tail blocks 28 at points higher in the sections (FIGS. 4-6), so that a power-driven winding drum 30 in the cab can extend the boom in the order of FIGS. 1-3, whereas the weight of the sections operates to retract the boom in reverse order when the drum 30 is released under the control of a braking mechanism 32 thereon.

When raised and extended, the boom carries an operating cable 34 which is rigged over a pair of tandemly arranged head sheaves 36 on the upper end of the uppermost section, so that the cable can be used to raise and lower a hook, grapple or other such operating means 38 attached to the distal end of the cable. The action of the cable 34 is controlled by another power-driven drum 40 about which it is wound in the cab.

As indicated, each of the pendants 18 and 20 is capable of supporting the boom in its raised position. However, only each of the longer main pendants 20 is effective to support the boom when it is extended under load, such as when the operating cable 34 is in use thereon. Referring again to FIGS. 1-3, and to FIGS. 4-7 in addition, it will be seen that the shorter hoist pendants 18 are fixed to anchorages 42 at the upper end of the lowermost section 2'; whereas the longer main pendants 20 are rigged over head blocks 44 on the upper end of the uppermost section 2", and then returned to the cab, there being stop sleeves 46 on the return portions of the longer pendants which are adapted to abut the blocks 44 when the longer pendants support the boom, and an auxiliary winch (not shown) on the cab for reeling in the return portions of the pendants when the boom is shortened in length. During the operation of raising and lowering the boom to and from its operatively extended condition, a control mechanism 48 on the lowermost section 2' is employed in conjunction with the shorter hoist pendants 18 to shift the load of the boom from the shorter pendants to the longer pendants 20, and vice versa. The mechanism 48 comprises a pair of hydraulic cylinders 50 which are pivotally mounted on the upper end of the lowermost section, in transverse relationship to the shorter pendants. The pistons 52 of the cylinders have arcuate shoes 54 thereon in which the shorter pendants are saddled, so that extension and retraction of the pistons operates to form and collapse bends 18' in the pendant when they are in tension. The beads 18' are employed as a means of adjusting the effective length of the shorter pendants relative to the straight line courses between the bridle 17 and the anchorages 42. The adjustment has the effect in turn, of altering the tension in the same, so that the boom is pivoted relatively toward or away from the ground, depending upon the direction of adjustment. As the boom pivots, the longer pendants 20 either take up the load or relinquish the load, since a point is passed at which the tension in one pair of pendants is transferred to the other assuming that the stroke of the pistons 52 exceeds the slack of those pendants which are relaxed.

Thus in raising the boom to its fully extended condition, the first step is to elevate the nested sections to a position substantially coincident with the desired operative position of the boom, using the sheave and drum winding mechanism 10. Then the cylinders 50 are actuated to pivot the boom upwardly through a slightly greater distance, such as to a limit position defined by a pair of telescoping boom stops 56 (FIGS. 1-3) which are pivotally interconnected between the cab 8 and the lowermost section 2' of the boom. Thereafter, while the resulting bends 18' remain in the shorter pendants, the upperrnost section 2" is extended from the intermediate section 2" to the condition of FIG. 2, and still later, the intermediate section 2" is extended to the condition of FIG. 3. Finally, after the slack in the longer pendants 20 has been taken up by the auxiliary winch to the extent that the stop sleeves 46 on the latter pendants abut the blocks 44, the cylinders 50 are retracted to collapse the bends, and thus to shift the load of the boom into the longer pendants 20.

In lowering the boom to its traveling position, the reverse is done in that first, the cylinders 50 are actuated to shift the load of the boom back to the shorter pendants, and then the boom is collapsed and lowered to the dot-dash condition of FIG. 1.

Referring now to FIGS. 4-11, it will be seen that each of the boom sections 2', 2", and 2" has a diamond-shaped cross section and comprises four parallel tubular stringers 58 interconnected by a crosswork of truss members 60 which impart body to the section. The sections are slideably interconnected with one another for the telescoping action by arcuate slides 62 which are interposed between the stringers 58 of the respective sections at regular intervals along the length of the boom. As the sections are unnested and telescoped into their extended positions, latch means 64 on the laterally disposed stringers operate to maintain the sections in position. The latch means comprises sets of bell-crank or dog-leg shaped pawls 66 which are pivotally mounted within yoke-like brackets 68 at the forward or upper ends of the stringers. The brackets are angularly disposed with respect to the stringers and project from the ends of the same in both the laterally outward and longitudinally forward directions so that the hinge pins 70 for the pawls are both raised from and forward of the stringers. Thus, the pawls can swing inwardly of their respective sections; and in doing so, will abut the stringers of each next higher section at their toes 66a. The latter have angularly recessed notches 72 therein, however, and when each next higher section assumes its extended condition, the toes 66a of the pawls engage in the notches 72 of the adjacent stringers, thereof the heels 66b of the pawls abut against the ends of the supporting stringers, to wedge the pawls between the sections, as indicated by the full line representations of the same in FIG. 10. In the case of the upper pawls 66", moreover, the engagement process is automatic in that the weight of each pawl generates sufiicient moment around its fulcrum to assure that it drops into the corresponding recess 72. However, in the case of the lower pawls 66 on the lowermost section, the engagement process is effected by pneumatically driven servomotors 74 which are mounted on the stringers behind the pawls, and pivotally connected to the bodies of the pawls at points spaced below the fulcra 70 thereof.

The motors 74 also serve to disengage the lower pawls 66' from their corresponding notches when the boom is collapsed. Thus, after the bends 18' are fonned in the shorter pendants 18, the next step in collapsing and lowering the boom is that of actuating the motors 74 in the direction of disengaging the pawls 66', while simultaneously actuating the sheave and drum winding mechanism 22 to lift the weight of the intermediate and uppermost sections from the toes of the pawls. The intermediate section 2" may then slip within the lowermost section as the pawls 66' slide over the outer surfaces of the stringers, there being screw-threaded stop pins 76 on the brackets 68 which limit the disengagement of the pawls.

The next step thereafter is to lower the uppermost section 2", but because of the telescoping arrangement of the sections, it is difficult to employ a similar set of pneumatically driven pawls for unlatching it. Therefore, the lower pawls 66 are also put to work in unlatching the uppermost section. Referring to FIGS. and 11 in particular, it will be seen that at the point of travel in which the upper end of the intermediate section 2" assumes a nested condition within the lowermost section 2", the toes 66a of the lower pawls 66 not only enter the ramped slots formed within the brackets 68 for the upper pawls 66", but also abut the heels 66b of the same of disengaging them from the notches. Thus, by applying the brakes 32 to the sheave and drum winding mechanism 22 at this point in the travel of the intermediate and uppermost sections, the operator can momentarily generate a sufiicient differential in the speed of the sections, due to the lighter weight of the uppermost section, to enable the upper pawls to disengage from the notches under the impetus given them by the lower pawls.

What I claim is:

1. In an outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal, and comprised of three elongated boom sections, the intermediate and uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof; latch means operatively interposed between the intermediate and uppermost sections to latch the latter sections against relative reciprocation when they are in the relatively extended condition thereof; a latch member which is mounted on the lowermost section and movable in relation thereto, to latch and unlatch the intermediate section against reciprocation with respect to the lowermost section when the intermediate section is in the relatively extended condition thereof; and means, operative to release the latch means between the intermediate and uppermost sections by positioning the latch member to engage the latch means when the latter sections have traveled a predetermined distance in relation to the lowermost section.

2. The outrigger device according to claim 1 wherein there is a recess in the uppermost section, and the latch means include a pawl which is rotatably carried on the intermediate section and operatively interposed between the recess and the adjacent end portion of the intermediate section to latch the intermediate and uppermost sections against relative reciprocation in the extended condition thereof.

3. The outrigger device according to claim 2 wherein the latch member includes a reciprocable displacement member for the pawl which is reciprocated in relation to the intermediate member to engage the pawl at a point in the retraction of the intermediate and uppermost sections at which the latter sections are caused to travel at a differential rate of speed in relation to the lowermost section, so that the pawl is displaceable from the recess when engaged by the displacement member.

4. The outrigger device according to claim 3 further comprising means for extending and retracting the intermediate and uppermost sections in relation to the lowermost section, including means for braking the travel of the uppermost section in relation to the intermediate section at the point where the pawl and the displacement member engage one another.

5. In an outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal, and comprised of three elongated boom sections, the intermediate and uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof; first and second latch means releaseably interposed between the intermediate section, and the uppermost and lowermost sections, respectively, to latch the respective section against relative reciprocation when they are in the relatively extended condition thereof; and latch release means mounted on the lowermost section to move in relation thereto, in response to release of the second latch means between the intermediate and lowermost sections, and operative to release the first latch means between the intermediate and uppermost sections, by engaging said first and second latch means when the latter sections have traveled a predetermined distance in so as to exert a pivotal force on the pawls 66" in the direction relation to the lowermost section-- 6. The outrigger device according to claim wherein there is a recess in the uppermost section, and the first latch means include a pawl which is rotatably carried on the intermediate section and operatively wedged between the recess and the adjacent end portion of the intermediate section to latch the intermediate and uppermost sections against relative reciprocation in the extended condition thereof.-

7. The outrigger device according to claim 6; wherein the latch release means includes a reciprocable displacement member for the pawl which is reciprocated in relation to the intermediate section to engage the pawl at a point in the retraction of the intermediate and uppermost sections at which the latter sections are caused to travel at a diiferential rate of speed in relation to the lowermost section, and operable to rotatably displace the pawl from the recess as the intermediate and uppermost sections travel beyond said point.

8. The outrigger device according to claim 7, wherein the displacement member is constituted by another pawl which is operatively wedged between a recess in the intermediate section and the adjacent end portion of the lowermost section to latch the intennediate section against reciprocation with respect to i the lowermost section, there being manually operated means for releasing this latter pawl from the latch position thereof when the intermediate and uppermost sections are to be retracted in relation to the lowermost section.

9. In an outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal, and comprised of three elongated boom sections, the intermediate and uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof, latch means operatively interposed between the intermediate and uppermost sections to latch the latter sections against relative reciprocation when they are in the relatively extended condition thereof, and a latch member which is mounted on the lowermost section and reciprocable in relation thereto, to latch and unlatch the intermediate section against reciprocation with respect to the lowermost section when the intermediate section is in the relatively extended condition thereof, said latch member being disposed to abut the lowermost section when reciprocated in the direction of 5 latching the intermediate section, and operative to release the latch means between the intermediate and uppermost sections by engagement therewith when reciprocated in the direction of unlatching the intermediate section.

10. The outrigger device according to claim 9, wherein there is a detent on the intermediate section and the latch member is reciprocable between a pair of positions, in one of which positions the latch member is engageable with the detent to be wedged between the lowermost and intermediate sections in the relatively extended condition of the intermediate section, and in the other of which positions the latch member is disengaged from the detent to allow the intermediate section to reciprocate in relation to the lowermost section, and moreover, engageable with the latch means between the intermediate and uppermost sections to release the latch means when the intermediate section has travelled a predetermined distance in relation to the lowermost section.

11. The outrigger device according to claim 10, wherein there is also a detent on the uppermost section 'and the latch means between the intermediate and uppermost sections includes a second latch member which is mounted on the intermediate section and similarly reciprocable between a pair of positions, in one of which positions the second latch member is engageable with the detent on the uppermost section to be wedged between the intermediate and uppermost sections in the relatively extended condition of the uppermost section, and in the other of which positions the second latch member is disengaged from the detent on the uppermost section to allow the uppermost section to reciprocate in relation to the intermediate section the first mentioned latch member being engageable with the second latch member to reciprocate the latter member from one to the other position thereof, when the intermediate section has travelled the predetermined distance in relation to the lowermost section-- 12. The outrigger device according to claim 11, wherein the detents take the form of recesses in the respective intermediate and uppermost sections, and the latch members take the form of pawls which are pivotally mounted on the relatively upper end portions of the respective lowermost and intermediate sections to be rotated into and out of engagement with the recesses, and to be engaged by one another when the relatively lower pawl is out of engagement with the recess corresponding thereto, and to release the relatively upper pawl when the intermediate and uppermost sections are travelling at a difi'erential rate of speed in relation to the lowermost section.--

* li It POW) UNITED STATES PATENT OFFICE CERIIFECATE OF CORRECTION Patent No. 3 r 674 r I Dated July 4 1972 Invenmfls) Tyman H. Fikse It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim 5, line 67 "section" should read sections Signed and sealed this 8th day of May 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. In an outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal, and comprised of three elongated boom sections, the intermediate and uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof; latch means operatively interposed between the intermediate and uppermost secTions to latch the latter sections against relative reciprocation when they are in the relatively extended condition thereof; a latch member which is mounted on the lowermost section and movable in relation thereto, to latch and unlatch the intermediate section against reciprocation with respect to the lowermost section when the intermediate section is in the relatively extended condition thereof; and means, operative to release the latch means between the intermediate and uppermost sections by positioning the latch member to engage the latch means when the latter sections have traveled a predetermined distance in relation to the lowermost section.
 2. The outrigger device according to claim 1 wherein there is a recess in the uppermost section, and the latch means include a pawl which is rotatably carried on the intermediate section and operatively interposed between the recess and the adjacent end portion of the intermediate section to latch the intermediate and uppermost sections against relative reciprocation in the extended condition thereof.
 3. The outrigger device according to claim 2 wherein the latch member includes a reciprocable displacement member for the pawl which is reciprocated in relation to the intermediate member to engage the pawl at a point in the retraction of the intermediate and uppermost sections at which the latter sections are caused to travel at a differential rate of speed in relation to the lowermost section, so that the pawl is displaceable from the recess when engaged by the displacement member.
 4. The outrigger device according to claim 3 further comprising means for extending and retracting the intermediate and uppermost sections in relation to the lowermost section, including means for braking the travel of the uppermost section in relation to the intermediate section at the point where the pawl and the displacement member engage one another.
 5. In an outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal, and comprised of three elongated boom sections, the intermediate and uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof; first and second latch means releaseably interposed between the intermediate section, and the uppermost and lowermost sections, respectively, to latch the respective section against relative reciprocation when they are in the relatively extended condition thereof; and latch release means mounted on the lowermost section to move in relation thereto, in response to release of the second latch means between the intermediate and lowermost sections, and operative to release the first latch means between the intermediate and uppermost sections, by engaging said first and second latch means when the latter sections have traveled a predetermined distance in relation to the lowermost section.--
 6. The outrigger device according to claim 5 wherein there is a recess in the uppermost section, and the first latch means include a pawl which is rotatably carried on the intermediate section and operatively wedged between the recess and the adjacent end portion of the intermediate section to latch the intermediate and uppermost sections against relative reciprocation in the extended condition thereof.--
 7. The outrigger device according to claim 6, wherein the latch release means includes a reciprocable displacement member for the pawl which is reciprocated in relation to the intermediate section to engage the pawl at a point in the retraction of the intermediate and uppermost sections at which the latter sections are caused to travel at a differential rate of speed in relation to the lowermost section, and operable to rotatably displace the pawl from the recesS as the intermediate and uppermost sections travel beyond said point.
 8. The outrigger device according to claim 7, wherein the displacement member is constituted by another pawl which is operatively wedged between a recess in the intermediate section and the adjacent end portion of the lowermost section to latch the intermediate section against reciprocation with respect to the lowermost section, there being manually operated means for releasing this latter pawl from the latch position thereof when the intermediate and uppermost sections are to be retracted in relation to the lowermost section.
 9. In an outrigger device which is mounted on an anchorage to be pivoted into an operatively inclined position relative to the horizontal, and comprised of three elongated boom sections, the intermediate and uppermost sections of which are relatively reciprocably engaged with one another, and conjointly reciprocably engaged with respect to the lowermost section, to be extended and retracted in relation to one another, and in relation to the lowermost section, along the length of the device while it is in the operatively inclined position thereof, latch means operatively interposed between the intermediate and uppermost sections to latch the latter sections against relative reciprocation when they are in the relatively extended condition thereof, and a latch member which is mounted on the lowermost section and reciprocable in relation thereto, to latch and unlatch the intermediate section against reciprocation with respect to the lowermost section when the intermediate section is in the relatively extended condition thereof, said latch member being disposed to abut the lowermost section when reciprocated in the direction of latching the intermediate section, and operative to release the latch means between the intermediate and uppermost sections by engagement therewith when reciprocated in the direction of unlatching the intermediate section.
 10. The outrigger device according to claim 9, wherein there is a detent on the intermediate section and the latch member is reciprocable between a pair of positions, in one of which positions the latch member is engageable with the detent to be wedged between the lowermost and intermediate sections in the relatively extended condition of the intermediate section, and in the other of which positions the latch member is disengaged from the detent to allow the intermediate section to reciprocate in relation to the lowermost section, and moreover, engageable with the latch means between the intermediate and uppermost sections to release the latch means when the intermediate section has travelled a predetermined distance in relation to the lowermost section.
 11. The outrigger device according to claim 10, wherein there is also a detent on the uppermost section and the latch means between the intermediate and uppermost sections includes a second latch member which is mounted on the intermediate section and similarly reciprocable between a pair of positions, in one of which positions the second latch member is engageable with the detent on the uppermost section to be wedged between the intermediate and uppermost sections in the relatively extended condition of the uppermost section, and in the other of which positions the second latch member is disengaged from the detent on the uppermost section to allow the uppermost section to reciprocate in relation to the intermediate section, the first mentioned latch member being engageable with the second latch member to reciprocate the latter member from one to the other position thereof, when the intermediate section has travelled the predetermined distance in relation to the lowermost section.--
 12. The outrigger device according to claim 11, wherein the detents take the form of recesses in the respective intermediate and uppermost sections, and the latch members take the form of pawls which are pivotally mounted on the relatively upper end portions of the respective lowermost and interMediate sections to be rotated into and out of engagement with the recesses, and to be engaged by one another when the relatively lower pawl is out of engagement with the recess corresponding thereto, and to release the relatively upper pawl when the intermediate and uppermost sections are travelling at a differential rate of speed in relation to the lowermost section.-- 